In many amplifier circuits, low noise performance generally is achieved by using relatively large resistors, and a separate error amplifier for common mode feedback. However, large resistors tend to result in relatively large area consumption. Also, a separate error amplifier can result in increased power consumption.
Another conventional solution involves DC coupled amplifiers. However, only one or two amplification stages are typically utilized in such an approach because of DC offset buildup. Other conventional solutions utilize ratios of resistors to set gain in a simple feedback scheme. However, these solutions may not easily lend themselves to changing the gain of the amplifier. Thus, a reliable and simplified low noise amplification approach that minimizes power consumption, operates over relatively large supply voltage range, and has an easily adjustable gain would be advantageous.